x86: isolate coherent mapping functions

i386 implements the declare coherent memory API, and x86_64 does not
it is reflected in pieces of dma_alloc_coherent and dma_free_coherent.
Those pieces are isolated in separate functions, that are declared
as empty macros in x86_64. This way we can make the code the same.

Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/arch/x86/kernel/pci-dma_32.c b/arch/x86/kernel/pci-dma_32.c
index 818d95efc3cb6deaeb2a8a8ac8414a5ae4d04879..78c7640252a4ecdb87f0bf79e3c4097e8e857a80 100644 (file)
--- a/arch/x86/kernel/pci-dma_32.c
+++ b/arch/x86/kernel/pci-dma_32.c
@@ -18,27 +18,50 @@
 dma_addr_t bad_dma_address __read_mostly = 0x0;
 EXPORT_SYMBOL(bad_dma_address);
 
-void *dma_alloc_coherent(struct device *dev, size_t size,
-                          dma_addr_t *dma_handle, gfp_t gfp)
+static int dma_alloc_from_coherent_mem(struct device *dev, ssize_t size,
+                                      dma_addr_t *dma_handle, void **ret)
 {
-       void *ret;
        struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;
        int order = get_order(size);
-       /* ignore region specifiers */
-       gfp &= ~(__GFP_DMA | __GFP_HIGHMEM);
 
        if (mem) {
                int page = bitmap_find_free_region(mem->bitmap, mem->size,
                                                     order);
                if (page >= 0) {
                        *dma_handle = mem->device_base + (page << PAGE_SHIFT);
-                       ret = mem->virt_base + (page << PAGE_SHIFT);
-                       memset(ret, 0, size);
-                       return ret;
+                       *ret = mem->virt_base + (page << PAGE_SHIFT);
+                       memset(*ret, 0, size);
                }
                if (mem->flags & DMA_MEMORY_EXCLUSIVE)
-                       return NULL;
+                       *ret = NULL;
+       }
+       return (mem != NULL);
+}
+
+static int dma_release_coherent(struct device *dev, int order, void *vaddr)
+{
+       struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;
+
+       if (mem && vaddr >= mem->virt_base && vaddr <
+                  (mem->virt_base + (mem->size << PAGE_SHIFT))) {
+               int page = (vaddr - mem->virt_base) >> PAGE_SHIFT;
+
+               bitmap_release_region(mem->bitmap, page, order);
+               return 1;
        }
+       return 0;
+}
+
+void *dma_alloc_coherent(struct device *dev, size_t size,
+                          dma_addr_t *dma_handle, gfp_t gfp)
+{
+       void *ret = NULL;
+       int order = get_order(size);
+       /* ignore region specifiers */
+       gfp &= ~(__GFP_DMA | __GFP_HIGHMEM);
+
+       if (dma_alloc_from_coherent_mem(dev, size, dma_handle, &ret))
+               return ret;
 
        if (dev == NULL || (dev->coherent_dma_mask < 0xffffffff))
                gfp |= GFP_DMA;
@@ -56,15 +79,11 @@ EXPORT_SYMBOL(dma_alloc_coherent);
 void dma_free_coherent(struct device *dev, size_t size,
                         void *vaddr, dma_addr_t dma_handle)
 {
-       struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;
        int order = get_order(size);
 
        WARN_ON(irqs_disabled());       /* for portability */
-       if (mem && vaddr >= mem->virt_base && vaddr < (mem->virt_base + (mem->size << PAGE_SHIFT))) {
-               int page = (vaddr - mem->virt_base) >> PAGE_SHIFT;
-
-               bitmap_release_region(mem->bitmap, page, order);
-       } else
-               free_pages((unsigned long)vaddr, order);
+       if (dma_release_coherent(dev, order, vaddr))
+               return;
+       free_pages((unsigned long)vaddr, order);
 }
 EXPORT_SYMBOL(dma_free_coherent);

diff --git a/arch/x86/kernel/pci-dma_64.c b/arch/x86/kernel/pci-dma_64.c
index e7d45cf82251f55dad94abfce099bc3ae4f0bbac..6eacd58e451bba9ce6a1bc29b8dcc76574412223 100644 (file)
--- a/arch/x86/kernel/pci-dma_64.c
+++ b/arch/x86/kernel/pci-dma_64.c
@@ -39,6 +39,8 @@ dma_alloc_pages(struct device *dev, gfp_t gfp, unsigned order)
        return page ? page_address(page) : NULL;
 }
 
+#define dma_alloc_from_coherent_mem(dev, size, handle, ret) (0)
+#define dma_release_coherent(dev, order, vaddr) (0)
 /*
  * Allocate memory for a coherent mapping.
  */
@@ -50,6 +52,10 @@ dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_handle,
        unsigned long dma_mask = 0;
        u64 bus;
 
+
+       if (dma_alloc_from_coherent_mem(dev, size, dma_handle, &memory))
+               return memory;
+
        if (!dev)
                dev = &fallback_dev;
        dma_mask = dev->coherent_dma_mask;
@@ -141,9 +147,12 @@ EXPORT_SYMBOL(dma_alloc_coherent);
 void dma_free_coherent(struct device *dev, size_t size,
                         void *vaddr, dma_addr_t bus)
 {
+       int order = get_order(size);
        WARN_ON(irqs_disabled());       /* for portability */
+       if (dma_release_coherent(dev, order, vaddr))
+               return;
        if (dma_ops->unmap_single)
                dma_ops->unmap_single(dev, bus, size, 0);
-       free_pages((unsigned long)vaddr, get_order(size));
+       free_pages((unsigned long)vaddr, order);
 }
 EXPORT_SYMBOL(dma_free_coherent);